For the above reasons, reliably and securely handling an otoscope of the art is currently subject to only well trained physicians and not amenable to the larger community of practitioners. A study recently published in the US as a result of a survey has shown that even physicians often fail to (correctly) determine the status of e.g. the subject's eardrum or fail to correctly interpret the image provided by the otoscope (i.e. correct and meaningful object recognition). Such failures result in misinterpretation of the status of the inner ear canal or the eardrum. As a consequence, e.g. over-medication with antibiotics for treating supposed inflammations of the eardrum occurs, because physicians tend to err on the side of caution, or meaningless image interpretation occurs.
Notably, there also exist other otoscopic devices, as e.g. video otoscopes, allowing a skilled expert to capture images of the subject's eardrum and the ear canal. Such video otoscopes comprise a bundle of light guides extending from the distal end of the head portion to a CCD-chip located remote from the distal end. The achievable resolution of the images depends on the number of light guides. In order to obtain images having a satisfying resolution, a significant number of individual light guides must be provided rendering devices by far too expensive for routine care. Moreover, all of the known video otoscopes having the CCD-chip located remote from the distal end of the head portion require superior handling skills by the physician. For the above reasons, they are not configured and suitable for domestic use by a larger community of practitioners, nor use by laypersons.
All otoscopes currently on the market—including video otoscopes—generally are based on the following fundamental design: a relatively thin open funnel. Length, angle, field of vision and size of the funnels are essentially similar for all marketed otoscopes. As a result of these common characteristics, ease of use (due to safety issues) is limited for such devices. Methods for reliable detection of objects in the ear canal, including the eardrum, are remarkably intricate with such known otoscopes.
Consequently, until today otoscopy has almost been exclusively applied by medical doctors. And even among medical doctors, only a minor percentage is sufficiently trained to carry out otoscopy in a reliable and appropriate way. However, since otitis media is the most frequent disease causing high fever in young children, and to exclude otitis media, especially OME, is a major reason for seeing a pediatrician, there is an urgent need for a parental check of the ear. Parents may also benefit from an otoscope that can be securely used by laypersons at home in order to check whether an ear canal of their child is blocked by massive earwax and/or foreign objects.
Prior art document U.S. Pat. No. 5,910,130 A describes an otoscope with a miniature video camera or a solid-state imager, e.g. a CCD or CMOS. A light source can be provided in the form of a continuous ring of light emitting fibres. The head portion of the otoscope has to be introduced far into a straightened ear canal in order to observe the eardrum.
Prior art document US2013/027515 A1 describes an ear canal side scanner with a small diameter comprising a camera including e.g. a CCD or CMOS chip. The camera can be arranged at a tip of a probe of the side scanner. The scanner allows for side scans of lateral surfaces of the ear canal. The tip of the side scanner is positioned close to the eardrum before scanning.
Prior art document US 2011/063428 A1 describes a medical device (an endoscope) comprising illumination means and a video camera based on wafer level optics, e.g. a solid state imager, and having a maximum outer diameter of less than 3.2 mm.
Prior art document EP 2 289 391 A1 describes an otoscope with a head portion and a fastening ring for reversibly mounting the head portion to a display portion.
Prior art document EP 2 277 439 A2 describes a clinical ear thermometer including an image sensor which is positioned radially offset, especially in order to provide a cavity in which a temperature sensor can be arranged at a distal end.
It is therefore an object of the present invention to provide an otoscope that allows for domestic application by laypersons and medical doctors without extensive otoscopy training and without any—or at least with a significantly reduced—risk of causing injuries to the patient. In particular, it is an object of the present invention to provide an otoscope that allows for automatically identifying objects within the ear canal, e.g. the eardrum, substantially irrespective of the relative position of a head portion of the otoscope within the ear canal. The object of the present invention can also be describes as to provide an otoscope that allows for identifying objects with high reliability, even if the otoscope is applied by laypersons.
This object is achieved according to the present invention by an otoscope exhibiting the features of claim 1 or claim 19 or claim 20. Preferred embodiments represent the subject-matter of the dependent claims.
In particular, this object is achieved by an otoscope of the generic type as described above, wherein the otoscope further comprises an optical electronic imaging unit positioned at the distal end of the head portion, especially at a distal tip of the head portion, wherein the electronic imaging unit exhibits at least one optical axis which is positioned radially offset from the longitudinal axis, and wherein the distal end is configured for accommodating the electronic imaging unit in such a way that the radial offset can be maximum with respect to the diameter of the distal end. The larger the radial offset, the better the view onto the eardrum, even in case the distal end is positioned only in a transition area between soft connective tissue and hard bone confining the ear canal. The electronic imaging unit may be arranged such that the radial offset is maximum with respect to the diameter of the distal end, in order to allow the otoscope for effectively looking around a curvature of the ear canal.
Providing a small electronic imaging unit at the distal end of the head portion exhibiting at least one optical axis which is radially offset allows to “see” the patient's eardrum without the need to deform the patient's ear canal, or at least without having to deform the ear canal to such an extent as with the above described conventional otoscope. The reason for this is that there is no need for the “viewing direction” of the electronic imaging unit to correspond to the longitudinal axis of the head portion of the otoscope. Rather, the radial offset can ensure that there is a line of sight onto the eardrum even if the ear canal is not straightened, allowing the device to “look around the corner”. In particular, in many cases, the ear canal of the outer ear is not straight-lined, but exhibits at least one curvature, especially at a transition area or transition point between soft connective tissue and hard bone confining the ear canal. The “corner” is provided by this curvature. In particular, virtually almost always, the ear canal has an S-shaped (sigmoid) form with a first curvature and a second curvature, the second curvature being closer to the eardrum than the first curvature. Particularly, the second curvature of the ear canal obstructs any optical line of sight or visual communication of an otoscope which is not introduced as far as at least some millimeters within the bony part of the ear canal. The “corner” can be defined as the second curvature of the ear canal. In particular, in a distal direction, the second curvature leads to the bony part of the ear canal. A transition point or area between soft connective tissue and hard bone is arranged at this second curvature. The second curvature leads into the section of the ear canal which is exclusively confined by hard bone. Preferably, the transition area can be defined as an area of about a few millimeters distal to (behind) and about a few millimeters proximal to (in front of) a curvature, especially 0 mm to 5 mm or 1 mm to 3 mm.
Such an electronic imaging unit can provide an otoscope which can be used by laypersons, without extensive otoscopy training and with a significantly reduced risk of causing injuries, especially with a significantly reduced risk of irritation of the patient's tissue, e.g. the tissue within the hard bone section of the ear canal. Such an electronic imaging unit allows for observing the eardrum substantially irrespective of the relative position of a head portion of the otoscope within the ear canal, especially irrespective of any specific insertion depth into the bony part of the ear canal, i.e. the section confined by hard bone. As the otoscope is arranged for “looking around the corner or curvature”, the layperson does not have to introduce the head portion as far as a section of the ear canal which is confined by hard bone. While in traditional otoscopy, the physician has to introduce the otoscope at least as far as some millimeters within the bony part of the ear canal, i.e. considerably further inwards than the second curvature, an otoscope according to the present invention can be positioned adjacent to the second curvature. In traditional otoscopy, the otoscope is necessarily introduced far into the bony part of the ear canal, especially in order to provide a kind of support or rest or anchoring point at the distal tip of the otoscope. Once the distal tip of the otoscope is supported within the bony part, the physician can apply a leverage on the handle portion of the otoscope, in order to straighten the ear canal and in order to ensure an optical line of sight onto the eardrum. But, this kind of “alignment” of the otoscope or this kind of straightening out the ear canal is painful. In contrast, the otoscope according to the invention does not require such an “alignment” or straightening.
According to one specific embodiment, the electronic imaging unit may also exhibit a field of vision with a wide angle, such that the eardrum is visible even in case the longitudinal axis is inclined with a large angle with respect to an longitudinal axis of the ear canal. According to another embodiment, the optical axis of the electronic imaging unit may also be arranged at an angle with respect to the longitudinal axis, allowing the device to “look around the corner” more effectively. An additional or alternative reason is that the field of vision of an electronic imaging unit provided at the distal end of the head portion can be much greater than the field of vision achievable with the relatively acute empty funnel of the otoscope according to the prior art.
Furthermore, in contrast to conventional otoscopes, the distal end of the head portion of the otoscope according to the present invention does not need to have a conical shape with a relatively thin open funnel, which shape bears the risk of introducing the distal end of the head portion too far into the ear canal, so as to cause serious injuries to the patient. Instead, the outer shape of the distal end of the head portion can be designed in such a way that it is practically impossible to introduce it too far into the ear canal. Thus, the otoscope according to the present invention can be securely and reliably operated even by laypersons without the risk of causing injuries to the patient. In particular, the otoscope according to the present invention allows for observing the eardrum substantially irrespective of the relative position of a head portion of the otoscope within the ear canal, especially irrespective of any specific insertion depth into the bony part of the ear canal, i.e. the section confined by hard bone. The distal end can be provided with a shape which allows for mechanically preventing any contact with the eardrum. In particular, the distal end can be provided with a relatively large diameter, which allows for both a large radial offset and a mechanical stop within the ear canal at a position relatively far away from the eardrum.
The distal end may exhibit a cavity for at least partially accommodating the electronic imaging unit such that the radial offset can be maximum within the lateral walls or lateral surface of the distal end, preferably at least half the radius (half of half the radial dimension) of the distal tip, more preferable at least ⅔ of the radius (or ⅔ of half the radial dimension) of the distal tip.
According to one embodiment, the radial offset is at least factor 0.25 of the radial dimension of the distal end, preferably at least factor 0.3, more preferable at least factor 0.35. Such a relatively large radial offset can ensure positioning the optical axis in a favorable eccentric observation point within the ear canal, even in case the distal tip in introduced only as deep as a transition point between soft connective tissue and hard bone.
According to one specific embodiment, the at least one miniature camera and/or the infrared sensor unit are positioned at a distance of less than 3 mm, preferably less than 2 mm, more preferable less than 1 mm, from the distal tip. Such an arrangement, especially as close as possible to the distal tip, allows for providing the maximum eccentricity within the ear canal, allowing for effectively “looking around the corner”.
According to one embodiment, adjacent to an inner lateral surface of the distal end, the head portion exhibits a cavity for accommodating an optical component (e.g. a camera, a lens or an image sensor) of the electronic imaging unit defining the at least one optical axis, such that the optical axis can be arranged as close as possible to the inner lateral surface of the distal end. Such a cavity ensures maximum radial offset. Preferably, the cavity at least partially is confined by the inner lateral surface of the distal end.
Preferably, the electronic imaging unit or at least an optical component thereof, e.g. a lens, is positioned at the most distal part of the head portion. In particular, the electronic imaging unit can be in contact with a front side or front face of the head portion, or the electronic imaging unit can provide a front side or front face of the head portion. This enables positioning the electronic imaging unit most distal within the ear canal without the need of introducing the head portion deep into the ear canal.
The otoscope according to the present invention may comprise further features that are provided, for example, by modern digital photo cameras. For example, the otoscope may comprise visual output means, such as a display, and/or acoustic output means, such as a loudspeaker, and/or a storage card slot for inserting a storage card to store the acquired images, and/or a cable connection port, such as an USB-port, and/or a wireless connection, such as Bluetooth®, WIFI®, and/or an energy supply, such as a battery.
Preferably, an “optical axis of the electronic imaging unit” is an axis which extends from a most distal point of the electronic imaging unit in a distal direction, especially towards the eardrum, wherein its orientation is not modified any more by any optical components. The “optical axis of the electronic imaging unit” of an electronic imaging unit preferably is the optical axis with the largest radial offset.
Preferably, the at least one optical axis is arranged as close as possible to an inner lateral surface of the distal end. Thereby, the radial offset can be maximized.
The electronic imaging unit may comprise a video camera defining an optical axis, preferable a wide angle color video camera. The term “wide angle” in this context refers to angels of at least 80°, preferably of at least 110°, e.g. 120°. Such wide angle cameras allow detection of the patient's eardrum, even if the optical axis of the camera is not directly centered to the eardrum and even if the eardrum is relatively remote from the camera, compared to the distance between the eardrum and the tip end of a conventional otoscope head during application. Using a color video camera is advantageous, allowing determination of the color of the eardrum and/or of the inner portion of the ear canal. Thus, inflammations can be detected by the degree of reddishness.
The electronic imaging unit may comprise a miniature camera, in particular a wafer-level camera of a substantially flat configuration, having dimensions of less than 3 mm×3 mm, preferably less than 2 mm×2 mm, especially 1.2 mm×1.2 mm, even more preferable of about 1 mm×1 mm or even less than 1 mm×1 mm. Wafer-level cameras refer to a relatively new technology. They can be produced small in size with only about 3 microns per pixel. Therefore, wafer-level imaging technology allows obtaining images of “sufficient” resolution of the eardrum, e.g. images of 250 pixels×250 pixels, with a footprint of the camera including lens of only about 1 mm×1 mm or even smaller.
The term “miniature camera” refers to cameras having minimum dimensions with respect to the required method of capturing images, preferably lateral or radial dimensions in the range of 0.5 mm to 2.5 mm, more preferably in the range of 0.5 mm to 1.5 mm, or 1 mm. A “miniature camera” may exhibit a diameter in the range of e.g. 0.5 mm to 1.5 mm. The dimensions of the camera in an axial direction (parallel to the longitudinal axis) is circumstantial, i.e. only of minor importance. Radial dimensions of less than 2 mm×2 mm, even more preferable of about 1 mm×1 mm provide the advantage that an optical axis of the electronic imaging unit or camera can be arranged very close to an inner or outer lateral surface of the head portion, thereby enabling the otoscope to “look around the corner” with a relatively big angle, e.g. an angle in the range of 10° to 60°, preferably in the range of 15° to 40°, more preferable in the range of 20° to 30°.
A camera based on wafer technology provides a good compromise between light sensitivity and space requirements. The light sensitivity depends on the dimensions of an aperture or lens of the camera. The bigger the aperture, the higher the light sensitivity.
A wide angle camera may enable the otoscope to “look around the corner”, in particular in conjunction with a radial offset and/or an optical axis which is tilted against the longitudinal axis of the head portion. A radial offset in conjunction with the ability of a “wide angle” may provide the advantage of “looking around the corner” without the need of an optical axis which is tilted. Nonetheless, the ability of “looking around the corner” can be ensured also by a camera being positioned radially offset and having an optical axis which is tilted. Most effectively, the ability of “looking around the corner” can be ensured by a wide angle camera which is positioned radially offset and which also has an optical axis which is tilted.
According to one specific embodiment, in addition to a radial offset, the electronic imaging unit exhibits a field of vision with a wide angle and/or at least one optical axis which is tilted against the longitudinal axis. Such an electronic imaging unit can provide an otoscope which is arranged for effectively “looking around the corner”, as the optical axis is positioned radially offset in conjunction with an optical axis which is tilted against the longitudinal axis and/or in conjunction with a field of vision with a wide angle.
According to one embodiment, the electronic imaging unit comprises at least one miniature camera, preferably at least three to six miniature cameras, especially four cameras, which respectively exhibits dimensions such that it can be arranged radially offset from the longitudinal axis of the head portion, wherein a radial offset with respect to an optical axis or a middle axis of the camera is in the range of 1 mm to 2.5 mm, preferably 1.5 mm to 2 mm, especially at least 1.8 mm. In other words: The type of imaging unit or the components of the imaging unit are chosen such that an imaging unit having at least one optical axis with a relatively large radial offset (especially with a maximum radial offset) with respect to the diameter of the head portion can be realized. A radial offset in these ranges may preferably be realized in conjunction with a relatively large diameter of the distal tip. Providing a radial offset of at least 1.8 mm facilitates “looking around a curvature”, even if the distal tip introduced only as deep as a transition area, and even in case an optical axis of the electronic imaging unit is positioned unfavorably.
In case the optical axes are provided by several cameras, preferably, the electronic imaging unit comprises at least three or four cameras, in particular miniature cameras, e.g. wafer-level cameras, which have dimensions such that all cameras can be arranged radially offset (with a maximum radial offset) from the longitudinal axis of the head portion. In particular, the electronic imaging unit comprises three or four miniature cameras, e.g. wafer-level cameras, each having dimensions of about 1 mm×1 mm. The present invention is based on the finding that such small cameras can be arranged with a radial offset which is large enough for enabling the otoscope to “look around the corner”, even if the distal tip of the head portion has a (relatively large) diameter in the range of e.g. 4.8 to 5.5 mm, mechanically stopping the head portion at a curvature or transition area between the two types of tissue within the ear canal.
In particular, especially with miniature cameras each having dimensions of about or even less than 1 mm×1 mm, a number of three cameras could be sufficient, as such small cameras can be positioned with a relatively high radial offset. The smaller the camera, the larger the realizable radial offset of an optical axis of the camera. A number of only three cameras also provides the advantage of reduced costs. In case the cameras have dimensions of e.g. about 1.2 mm×1.2 mm or 1.5 mm×1.5 mm, a number of four cameras is preferred. The higher the number of the cameras or optical axes, the higher the likelihood that at least one optical axis is positioned at a favorable eccentric position within the ear canal in order to entirely observe the eardrum. According to one embodiment, the electronic imaging unit comprises four cameras arranged at the same radial offset and having the same distance to each other in a circumferential direction.
A number of three, four, five or six miniature cameras or optical axes can eliminate any need for displacement or rotation of the head portion for positioning a camera in a preferred eccentric observation point. For example, with such an arrangement, it can be ensured that the head portion of the otoscope or the handle portion of the otoscope does not have to be rotated at all. In other words: The layperson only has to introduce the otoscope in an axial direction. It is not required to rotate any part of the otoscope. This reduced the probability of any irritations of the layperson's tissue. Preferably, the electronic imaging unit exhibits a plurality of optical axes which are arranged concentrically, especially rotationally symmetrically with respect to the longitudinal axis of the head portion. According to one embodiment, each optical axis may be provided by one camera.
Nonetheless, irrespective of the number of optical axes, additionally, a motion mechanism can be provided. Providing several cameras, e.g. two or three cameras, in conjunction with a motion mechanism provides the advantage that, if at all, the head portion or the otoscope only has to be rotated by a maximum angle of about 20° to 50°, in order to displace at least one of the cameras in a preferred position for “looking around the corner”. A rotating movement of maximum 40° or 50° can position at least one of the cameras in a position in which the eardrum is best visible. Thereby, the present invention is based on the finding that an angle of 40° or 50° can be handled or operated without any problems, especially in an ergonomic way by laypersons, even in context with an application by the layperson. Thus, providing at least two or three, especially four, optical axes may eliminate the need of any motion mechanism. It has been found that more than four cameras or optical axes are not necessarily required. Even, three cameras may be sufficient, in case each optical axis is positioned with a relatively large optical axis. Nonetheless, a number of four cameras seems to be preferred for most applications.
According to one specific embodiment, the electronic imaging unit comprises at least two cameras which exhibit radial dimensions such that they be arranged radially offset from the longitudinal axis of the head portion, wherein a radial offset with respect to an optical axis or a middle axis of the cameras is bigger than a quarter of the diameter of a distal tip of the head portion, preferably bigger than one third of the diameter of a distal tip of the head portion. Providing a camera with such small dimensions can facilitate the otoscope to “look around the corner”. The smaller the dimensions of the camera, the larger the radial offset which can be realized. Cameras with such radial dimensions can be arranged very close to the outer lateral surface of the head portion, i.e. very close to an inner lateral surface of the ear canal.
According to one embodiment, the electronic imaging unit comprises at least one camera or optical component like a lens which has radial dimensions which are smaller than ⅓, preferably smaller than ¼, more preferable smaller than ⅕ or ⅙ of a diameter of the distal end or distal tip of the head portion. Such relatively small radial dimensions can ensure that the radial offset is relatively large. Also, such relatively small radial dimensions can ensure that optionally, a plurality of cameras can be arranged on the same pitch circle, the pitch circle having a relatively large diameter.
According to one embodiment, the electronic imaging unit exhibits beam splitter optics defining at least two optical axes which are arranged radially offset from the longitudinal axis. Beam splitter optics provide the advantage that the eardrum can be observed from different points of the distal tip of the head portion, without the need of a plurality of cameras. With beam splitter optics, a relatively large radial offset of each optical axis can be realized, especially a radial offset which can be even larger than the radial offset of an optical axis defined by a camera (even in case a relatively small miniature camera is used). In particular, optical components of the beam splitter optics, such as lenses, mirrors or prisms, can be provided with relatively small radial dimensions. In particular, the optical components can be provided with a radial dimension or diameter smaller than 1 mm, preferably smaller than 0.9 mm, even smaller than 0.8 mm or 0.7 mm.
Also, beam splitter optics can provide an aperture which exhibits relatively large radial dimensions. A large aperture provides for good optical characteristics, especially good light sensitivity and/or a high dynamic range. Also, beam splitter optics can provide an arrangement for “looking around the corner” which is cost-effective.
According to one specific embodiment, the beam splitter optics define a plurality of optical axes which are arranged concentrically, especially rotationally symmetrically with respect to the longitudinal axis of the head portion. Such a design can ensure that the orientation of the head portion within the ear canal can be chosen freely by the user. The user does not have to orientate the handle portion of the otoscope in a specific direction.
Alternatively or in addition, the at least one of the optical axes may be tilted against the longitudinal axis so as to be directed to a predetermined point on the longitudinal axis. Beam splitter optics can provide an arrangement with optical axes with a relatively large tilt angle against the longitudinal axis of the head portion, allowing for “looking around the corner” more effectively than any arrangement with parallel optical axes or with relatively small tilt angles.
Preferably, the electronic imaging unit exhibits an image sensor which is optically coupled with the beam splitter optics, especially with at least two of the optical axes, and which is positioned centrically on the longitudinal axis. An image sensor which is positioned centrically can provide a symmetric design of the imaging unit, which can be favorable also in view of constructing or manufacturing aspects. An image sensor which is arranged centrically can exhibit large radial dimensions, especially as the image sensor can be arranged more proximal in a section of the head portion which exhibits larger radial dimensions than the distal tip. Preferably, the image sensor is provided in conjunction with a plurality of optical axes, e.g. in conjunction with beam splitter optics. In other words: The electronic imaging unit is configured for providing an arrangement with a single image sensor and multiple optical axes. Reducing the number of image sensors can provide an otoscope with a straightforward design, which is cost-effective.
The image sensor may exhibit radial dimensions which are larger than the radial dimensions of any optical component arranged at a distal tip of the otoscope, preferably at least 0.7 mm, more preferable at least 1 mm, further preferred at least 1.5 mm, especially between 1.5 mm and 3 mm. An image sensor which is spaced apart from the distal tip and which is arranged separately from any optical component at the distal tip can be provided with larger (radial, i.e. lateral) dimensions than the optical component, especially any aperture. In particular in conjunction with a conical shape of the head portion, arranging the image sensor proximal to the optical component at the distal tip provided more lateral space (in the radial direction) within the head portion. The larger the image sensor, the better the optical characteristics. In particular, a large image sensor is advantageous for light sensitivity, dynamic range and/or resolution.
The beam splitter optics may comprise at least one mirror and/or prisms and/or at least one lens. These components can provide a high flexibility with respect to the design of the electronic imaging unit. Also, these components allow for large radial offsets, especially as its radial dimensions can be relatively small, e.g. even smaller than the radial dimensions of a miniature camera. For example, the beam splitter optics may comprise at least one prism which exhibits an integral lens. A prism directly including a lens, especially a prism with an integral lens which is made of the same material as the prism, can provide an otoscope with a straightforward design, wherein restricted space conditions within the distal end of the head portion can be exploited. Preferably, an integral lens is a lens which is formed by the prism.
Alternatively or in addition, for each optical axis, the beam splitter optics may comprise concave mirrors, especially two concave mirrors which preferably are provided as aspherical surfaces, wherein a radial offset of the respective optical axis is defined by the two concave mirrors. The relatively low number of only two mirrors for each optical axis can provide an otoscope with a straightforward design, wherein restricted space conditions within the distal end of the head portion can be exploited.
Also, for each optical axis, the beam splitter optics may comprise a plurality of lenses or surfaces, especially two refractive and reflective surfaces and two refractive surfaces, wherein the respective optical axis is defined by the plurality of surfaces. A plurality of optical surfaces can provide high optical fidelity. A suitable combination of refractive and/or reflective aspherical surfaces allows for realization of the desired optical characteristics in a single optical element or block, which can e.g. be a single injection molded PMMA part. The single injection molded part can provide both a support or housing and optical components like lenses.
In particular, for each optical axis, the beam splitter optics can be provided with two refracting lenses and with two both refracting and reflecting lenses. Preferably, the reflecting lenses are tilted with respect to the optical axis, such that a radial offset can be realized.
Alternatively or in addition, for at least one optical axis, the beam splitter optics comprise an optical fibre, especially a gradient index fibre, wherein the respective optical axis is defined by the optical fibre, wherein the respective optical fibre preferably extends between an image sensor of the electronic imaging unit and a distal tip of the head portion. An optical fibre allows for different arrangements of the components of the beam splitter optics with respect to each other. An optical fibre allows for tilting the optical axis. There is no need for any complex arrangement consisting of a plurality of optical components. An optical fibre allows for maximum radial offset irrespective of the space conditions within the distal end or irrespective of any geometrical constraints within the distal end. Also, an optical fibre allows for arranging an image sensor at a relatively large distance from the distal tip, in order to allow for large radial dimensions of the image sensor. Also, an optical fibre allows for minimized use of optical parts or surfaces, i.e. for reduced complexity.
As described above, the specific features of the beam splitter optics may be combined with each other, in order to provide a specific (optimized) electronic imaging unit with respect to specific applications or groups of people.
According to one embodiment, the electronic imaging unit comprises a support or housing defining the radial offset of at least one optical axis and/or accommodating at least one camera and/or beam splitter optics, wherein the support preferably is in contact with an inner lateral surface of the distal end. The support enables exactly positioning or orientating at least one camera, especially a wafer camera, or at least one optical axis of beam splitter optics within the head portion, especially with respect to the longitudinal axis of the head portion. In particular, the support enables concentric arrangement of the optical axes. Concentric arrangement may ensure maximum radial offset irrespective of the rotational position of the head portion within the ear canal.
Preferably, the beam splitter optics are arranged such that the optical axes are positioned with a radial offset which is maximum with respect to the radial dimensions of the distal end. The beam splitter optics can provide an optical path which is directed in the radial direction for an amount or distance which is maximum with respect to the diameter of the head portion. The beam splitter optics can provide a relatively large radial offset. In particular, at least two optical surfaces of an optical path are arranged in a tilt angle with respect to the longitudinal axis such that a maximum radial offset can be realized. Alternatively, two concave mirrors are provided with a surface which is shaped such that a maximum radial offset can be realized.
According to one specific embodiment, the support or housing exhibits an outer lateral surface with a convex shape, at least in sections. A convex shape can ensure that a respective optical axis can be positioned as close as possible to an inner lateral surface of the distal end or tip, adjacent to the inner lateral surface, in order to provide a maximum radial offset with respect to the diameter of the distal end or tip. Preferably, the support encircles the electronic imaging unit, at least its distal end. Also, optionally, a component of the electronic imaging unit, e.g. a camera, can be fixed and/or centered directly at the inner lateral surface, at least partially.
One optical axis of the electronic imaging unit may be positioned substantially centrically with respect to the longitudinal axis of the head portion. If one optical axis of the electronic imaging unit is positioned on the longitudinal axis of the head portion, a substantially flat optical component of the electronic imaging unit is preferable inclined or inclinable with respect of the longitudinal axis of the head portion, so that the one optical axis (or a “viewing direction”) of the electronic imaging unit is angled with respect to the longitudinal axis (tilted against the longitudinal axis) of the head portion, allowing the otoscope to “look around the corner” even from a central observation point.
As describes above, the electronic imaging unit may comprise at least one optical axis, e.g. provided by a camera, preferably at least three or four optical axes provided by at least three or four wafer-level cameras which is/are positioned radially offset from the longitudinal axis of the head portion. Such a configuration also allows obtaining a free view onto the eardrum without having to introduce the electronic imaging unit as deeply as it would be necessary if the electronic imaging unit only had one optical axis placed just centrally on the longitudinal axis of the head portion. The offset of all three or four optical axes may be at least 1 mm, preferably at least 1.7 mm, more preferably at least 1.8 mm or at least 1.9 mm, or even (if possible) at least 2.2 mm or 2.5 mm from the longitudinal axis. Preferably, the maximum radial offset is within the limits of the outer diameter of a distal tip of the head portion. The radial offset is in the range of 1 mm to 2.5 mm, preferably 1.5 mm to 2 mm, especially at least 1.8 mm, especially with respect to an optical axis or a middle axis of the at least one camera. An arrangement with a large radial offset, especially in conjunction with a large diameter of the distal tip of the head portion, enables positioning of the camera or an optical axis as close as possible adjacent to an inner wall of the ear canal such that the eardrum can be observed from a preferred position within the ear canal, without the need of introducing the distal tip as far as to the hard bone section of the ear canal.
Preferably, the at least one camera is arranged adjacent to an inner lateral surface of the head portion in such a way that the radial offset is maximum with respect to the radial dimensions of the head portion. Thereby, the radial offset can be maximized.
The optical axis of the at least one camera may be tilted against the longitudinal axis so as to be directed to a predetermined point on the longitudinal axis, the predetermined point having a fixed distance to the at least one camera. A tilted optical axis provides the advantage that, substantially irrespective of the relative position of a head portion of the otoscope within the ear canal, it is more likely that the entire eardrum can be observed.
According to one specific embodiment, the head portion exhibits a supporting structure for fixing a camera of the electronic imaging unit, wherein the supporting structure at least partially radially extends from the longitudinal axis to an inner lateral surface of the head portion, such that the camera can be supported in a position with maximum radial offset.
The head portion is preferably shaped such that (and exhibits radial dimensions such that) its distal end comprising the electronic imaging unit can be introduced only as deep into the ear canal as not to touch the eardrum, especially only as deep as not to touch the hard bone, or at most only as far as some millimeters within the section confined by hard bone. The ear canal of the patient's outer ear is limited by the eardrum. Notably, the ear canal of the patient's outer ear comprises an outer part which refers to a portion of the patient's outer ear (i.e. the patient's external auditory canal) that is surrounded by soft connective tissue and that usually comprises hair and earwax. The outer part comprises approximately the outer half of the ear canal of the patient's outer ear. Furthermore, the ear canal of the patient's outer ear also comprises an inner part which refers to a portion of the patient's outer ear (i.e. the patient's external auditory canal) that is surrounded by hard skull bone and that is usually free from any hair and earwax. This portion extends from the proximal end the outer part of the ear canal of the patient's outer ear to the eardrum. The inner part of the ear canal is very sensitive to pain in case of injury by mechanical friction. Injuring the inner part of the ear canal even bears the risk of cardiovascular complications through vagal overstimulation.
Preferably, the head portion is shaped in such a way that its distal end comprising the electronic imaging unit can be introduced only in an area of the ear canal which is confined by soft connective tissue, but not in an area of the ear canal which is confined by hard bone. On the one hand, such a shape can ensure that the distal end does not touch the eardrum, even if the otoscope is applied by laypersons. On the other hand, the otoscope can be applied by layperson without the need of correcting the position of the head portion within the ear canal. Rather, the head portion only has to be positioned “somehow” within the ear canal, which even can be made by the same person. In other words: There is no need of any assistance at all, which is favorable e.g. for an application by older people living on one's own. The otoscope according to the present invention even can enable an application by the layperson. In particular, the otoscope is arranged to “look around the corner” such that it is sufficient to introduce the head portion only in an area of the ear canal which is confined by soft connective tissue.
Preferably, a tip portion of the distal end can be introduced into the ear canal of the patient's outer ear no further than to a distance from the eardrum of at least a few millimeters, preferably of at least 3 mm, more preferable of at least 10 mm, further preferred of at least 15 mm.
As already mentioned above, the tapering head portion of the otoscope according to the present invention can be shaped with a blunt, rounded tip end, as compared to a conventionally known otoscope, thereby reducing the risk of introducing injury or discomfort to the patient. Thus, the device can be securely handled by laypersons. The otoscope according to the present invention, nevertheless, allows detecting the eardrum, since the electronic imaging unit is provided at the distal end of the head portion, exhibiting at least one optical axis which is radially offset.
Preferably, the distal end of the head portion is provided with a round and smooth shape. Moreover, the distal end may be made from a relatively soft material, such as silicone, or it may comprise an outer surface made of such a soft material. Furthermore, the longitudinal force upon introduction into the ear canal can be limited by a telescoping mechanism or the use of an elastic element.
The functional concept of a conventional otoscope as described above, however, requires the tip end of the head portion to be relatively small and acute (sharp), usually having a diameter of only about 3 mm. It is noted that the diameter of the inner part of the outer ear canal of an adult is about 4 mm. Therefore, if the user (untrained) does not pay attention, the tip portion might be introduced deeply into the inner part of the outer ear canal causing serious injuries to the patient. To substantially avoid this risk, the head portion of the otoscope according to the present invention (also having a tapered shape) preferably exhibits a diameter of at least 4 mm, preferably of more than 5 mm, more preferably of more than 6 mm, at a position along the longitudinal axis of the head portion of no more than 4 mm from a distal end point of the head portion. Thus, it is geometrically excluded to introduce the distal end of the head portion too far into the subject's ear canal. Different geometries of tapers may preferably be used according to the age group of the subject. For children, for example, the head portion of the otoscope adapted to carry out the method according to the present invention may exhibit a diameter of about 5 mm at a position along the longitudinal axis of the head portion of no more than 4 mm away from a distal end point of the head portion. For example, the head portion can be provided with a first specific shape for children at the age of 0 to 2 years and with a second specific shape for any patient at the age of more than 2 years. But, it is not necessarily required to use different geometries of tapers according to the age group of the subject. Rather, the inventive shape of the head portion can be used by all age groups, as it is not required to introduce the head portion far into the subject's ear canal. Thus, the inventive shape of the head portion can provide a universal speculum.
According to one embodiment, the distal tip of the head portion exhibits a diameter, especially an outer diameter, of at least 4.0 mm, at least 4.7 mm, preferably of more than 4.8 mm, more preferably about 4.9 mm. A head portion with a distal tip having a diameter of about 4.7 mm, 4.8 mm or 4.9 mm is not adequate or appropriate for classical otoscopy, especially for observing the eardrum of a child. Such a relatively large tip could not be inserted into the ear canal as far as considerably within the bony part, especially in childrens' ears. The head portion would be blocked at a position too far away from the eardrum, at least within ears of children. It would not be possible to observe the eardrum. There would not be any line of sight onto the eardrum. It would not be possible to align the otoscope within the ear canal such that the eardrum is visible. The head portion would not be introduced far enough for aligning the entire ear canal.
In contrast, according to the present invention, a distal tip with a diameter of about 4.7 mm, 4.8 mm or 4.9 mm can ensure that the distal tip cannot be inserted further into the ear canal than a position within the part of the ear canal which corresponds to a transition area between soft connective tissue and hard bone surrounding the ear canal. In particular, at most, the distal tip of the head portion is docked to or coupled to a proximal end of the bony part. At most, the distal tip of the head portion is positioned at the outer end of the bony part of the ear canal, but not further inwards. In other words: The head portion of the otoscope is preferably shaped in such a way that its distal end comprising the electronic imaging unit or optical component (e.g. camera) can be introduced only as deep into the ear canal as a transition area between soft connective tissue and hard bone confining the ear canal. Preferably, a diameter of an inner lateral surface of the distal end is in the range between at least 4.2 mm, preferably more than 4.4 mm, more preferably about at least 4.5 mm or 4.6 mm, in order to allow maximum radial offset.
The present invention is based on the finding that it is not required to introduce the distal end as far as considerably within the part of the ear canal which is confined by hard bone. Rather, the electronic imaging unit allows for “looking around the corner” even in case the distal tip is introduced only as deep as a transition area between the two types of tissue. Therefore, the electronic imaging unit arranged at the distal tip comprises a camera which preferably exhibits a wide angle, and/or at least one optical axis which is arranged radially offset adjacent to and as close as possible to an inner lateral surface of the distal tip, and/or which has an optical axis which is tilted against the longitudinal axis of the head portion.
In other words: Due to the ability of “looking around the corner”, it is possible to shape the head portion such that any contact of the distal tip with the eardrum or even with the bony part of the ear canal can be prevented, especially mechanically. In particular, the present invention is also based on the finding that the ability of “looking around the corner” may permit to provide only one single shape of a head portion, i.e. a kind of “one size fits all” ages or people head portion.
According to one specific embodiment, the head portion exhibits a conical portion with an opening angle α in the range of 3° to 10°, preferably 4° to 8°, especially 5° or 6°. Such opening angles can ensure that, in case the layperson tries to introduce the head portion as far as a section of the ear canal which is confined by hard bone, further insertion of the head portion is blocked within the ear canal well before reaching the eardrum.
According to one specific embodiment, the head portion exhibits a distal tip with a first diameter (d1) in the range of 4 mm to 6 mm, preferably 4.5 mm to 5.3 mm, further preferred 4.7 mm to 5.1 mm, especially 4.9 mm. At a longitudinal position defined by a specific length, the head portion preferably exhibits a second diameter (d2) in the range of 7.5 mm to 9.5 mm, preferably 8 mm to 9 mm, further preferred 8.3 mm to 8.8 mm especially 8.5 mm. Preferably, the ratio of these diameters (d1:d2) is in the range of 0.57 to 0.65, especially about 0.58 or about 0.63. Such a shape can ensure that the head portion is blocked well before reaching the eardrum. Preferably, the specific length is in the range of 18 mm to 22 mm, more preferable 19 mm to 21 mm, especially 20 mm. These diameters or ratios can ensure that the head portion, especially the distal end, exhibits geometrical dimensions ensuring that the head portion can be introduced only in the area of soft connective tissue confining an outer ear canal of the patient's outer ear, but not in the area of hard bone confining the outer ear canal. Such a shape can ensure that the otoscope can be applied by laypersons without the risk of irritations of the tissue.
According to one specific embodiment, the electronic imaging unit exhibits at least one camera with an optical axis which is tilted against the longitudinal axis, wherein the distal end exhibits a conical shape, preferably with a tilt angle (β1) between the longitudinal axis and a lateral surface of the distal end which at least approximately corresponds to the tilt angle of the optical axis. Such a design facilitates an arrangement of the camera with a maximum radial offset. Also, a conical shape of the distal end can facilitate mechanically blocking the head portion within a transition area between the two types of tissue. Preferably, the tilt angle is variable and can be increased.
According to one specific embodiment, at the distal end, the head portion exhibits a maximum wall thickness in the range of 0.1 mm to 0.5 mm, preferably 0.12 mm to 0.3 mm, more preferably 0.13 mm to 0.2 mm, especially 0.15 mm at the maximum. Such a relatively low wall thickness enables positioning the (respective) optical axis with a maximum eccentricity with respect to the radial dimensions of the distal tip. The lower the wall thickness, the larger the radial offset which can be realized.
According to one specific embodiment, the head portion and/or the handle portion exhibits fixation means for fixing a probe cover at the otoscope. Thereby, a probe cover can be fixed at the head portion or handle portion such that relative motion can be prevented. Such fixations means can prevent premature unfolding of the probe cover, as relative motion between the head portion and a probe cover is only enabled at a time when the distal tip is introduced far enough. The risk of ear wax obstructing visual communication can be minimized.
The features relating to the shape of the head portion, as described above, may be combined with each other, in order to make the concept of “looking around the corner” more practicable, even in context with an application by laypersons.
When introducing the tip end of the head portion no deeper into the ear canal than to the border between the outer part and the inner part of the outer ear canal of the patient's outer ear, i.e. to a transition area between the two types of tissue, there is the risk that artifacts, such as earwax, hair and other kind of dirt from the outer part of the outer ear canal obstruct the view of the small electronic imaging unit onto the patient's eardrum. Therefore, it is advantageous to take several images from different positions within the ear canal. For doing so, the otoscope according to the present invention may comprise more than one optical axis or cameras at the distal end of its head portion, e.g. two optical axis or cameras, located at different positions on the head portion, wherein the otoscope comprises a logic unit which is configured for controlling each camera or beam splitter optics for capturing a plurality of different images, especially from eccentric observation points which are arranged on the same semi circle of an at least approcimately circular cross section of the ear canal.
In another preferred embodiment, the otoscope according to the present invention further comprises a motion mechanism configured to allow displacement of the electronic imaging unit or the at least one optical axis of the electronic imaging unit or at least one camera of the electronic imaging unit relative to the handle portion. With such a motion mechanism, it is possible to position the at least one optical axis in a favorable eccentric observation point, substantially irrespective of the position of the head portion within the ear canal. Also, with such a motion mechanism, it is possible to capture a plurality of images from different positions from one optical axis within the patient's ear canal, thereby avoiding the need for two or more cameras. If, for example, a hair—at least partially—obstructs the view of the electronic imaging unit at a certain position within the ear canal onto the eardrum, the electronic imaging unit may have a free view onto the eardrum at another position in the ear canal or may at least have a free view onto the part of the eardrum that was partially obstructed by the hair before.
It has been found that positioning the at least one optical axis radially offset induces or brings about that the eccentric observation point positioned at the distal tip on this least one optical axis may be positioned at an unfavorable position, e.g. adjacent to a section of the ear canal having a minimal radius of curvature. Therefore, departing from at least one a radially offset optical axis, the motion mechanism may facilitate to make the concept of “looking around the corner” more practicable.
Moreover, providing such a motion mechanism also allows for automatic identification of different objects in the patient's ear. Usually, in otoscopy, the eardrum represents the object of primary interest. In contrast, artifacts, such as earwax, hair and other kind of dirt, are usually of no particular interest. Such artifacts rather represent a problem when obstructing the view onto the patient's eardrum.
However, since artifacts are relatively close in front of the electronic imaging unit in the ear canal, compared to the eardrum, the artifacts can be distinguished from the eardrum when displacing the electronic imaging unit within the ear canal. That is, artifacts are depicted at distinct positions, if two images are captured from different positions/perspectives within the ear canal (due to their short distance to the electronic imaging unit), whereas the eardrum is shown substantially at the same position (due to the relatively large distance to the electronic imaging unit). According to the principle of stereoscopic viewing, the inventive device enables to determine the distance of different objects with respect to the electronic imaging unit. This determination can be automatically calculated by means of a logic unit, such as a microprocessor, preferably forming part of the otoscope. Furthermore, objects that have been identified as artifacts (due to their close distance to the electronic imaging unit) may be (automatically) eliminated by the image processing unit by comparing two or more images captured from different positions within the patient's ear canal. Consequently, a superimposed image may be generated or calculated by image processing means eliminating the artifacts. The image processing means may be implemented in form of a logic unit, such as a microprocessor provided in the otoscope. Thus, an image clearly depicting the eardrum can be obtained, even if the tip end of the head portion is introduced into the ear canal to the border between the outer part and the inner part of the outer ear canal (and not deeper into the ear canal).
The motion mechanism may be arranged within the handle portion, wherein the motion mechanism preferably includes a drive shaft which is preferably arranged on the longitudinal axis. Preferably, the motion mechanism is arranged completely separate from the head portion. Such an arrangement can provide a straightforward design with low acoustic emission into the ear.
Preferably, the motion mechanism includes a motor. A motor allows for automatically position the optical axis. The motor can be provided e.g. in the form of a brushless motor, especially in order to minimize any noise evoked or generated by the motor. Brushless motors can be accelerated softly by ramp up of angular speed of the rotating magnetic field. Rotational vibration can be minimized. A noise reduced brushless motor provides the advantage that any noise or acoustic emission of the motor does not trouble or confuse the patient during the application of the otoscope. Preferably, the motion mechanism, especially the motor is configured for rotating the electronic imaging unit by an angle of about 180°.
The motion mechanism is preferably configured to allow at least partial rotation of the electronic imaging unit or the at least one optical axis or the at least one camera about an axis of rotation. The axis of rotation may correspond to the longitudinal axis of the head portion. By displacing the electronic imaging unit along a predefined motion path, it is possible to automatically calculate the distance of the electronic imaging unit to the detected objects, as described above. In view of the typical size of the artifacts found in the ear canal, such as hair and earwax particles, the motion mechanism preferably allows for displacement of the optical axis of at least 1 mm, more preferable at least 2 mm, further preferred at least 3 mm, within the patient's ear canal. For example, in case a radial offset of 1.8 mm or 2 mm is realized, a rotation of 90° evokes a displacement of about 3 mm. A rotation of at least 90°, more preferably of at least 120°, even more preferably of 180° or even more degrees around the axis may be realized. In conjunction with an electronic imaging unit exhibiting two optical axes or comprising two cameras, a rotation of maximum 90° may be adequate in order to find the most favorable eccentric observation point. In conjunction with an electronic imaging unit exhibiting three optical axes or comprising three cameras, a rotation of maximum 60° or 70° may be adequate. Preferably, the motion mechanism allows for rotation in both directions, i.e. clockwise and counter-clockwise. The motion mechanism may also allow for rotational displacement about more than one axis. The motion mechanism may comprise at least one motor and one or more gears and/or bearings. The electronic imaging unit may be connected to a flexible cable, e.g. a flexible ribbon cable, to allow for such a movement.
An axis of rotation corresponding to the longitudinal axis of the head portion allows for displacing the at least one optical axis concentrically around the longitudinal axis. Thus, irrespective of the relative position of the optical axis, a maximum radial offset can be ensured.
Preferably, an optical component of the electronic imaging unit or at least one optical axis of the electronic imaging unit or at least one camera is tilted against the axis of rotation so as to be continuously directed to a predetermined point on the axis of rotation, especially during a rotation by the motion mechanism, the predetermined point having a fixed distance to the electronic imaging unit or to the camera. In view of the typical length of the inner part of the outer ear canal of the patient's outer ear, the distance may be between 3 mm and 20 mm, preferably between 10 mm and 15 mm. Thus, the “viewing direction” of the electronic imaging unit is optimized for centering on the eardrum, which usually represents the object of primary interest within the patient's ear. Also, the “viewing direction” remains directed onto the central point of interest, even in case there is relative rotation induced by the motion mechanism. In conjunction with a specific shape of the head portion ensuring that the distal tip is mechanically blocked at a transition area between the two types of tissue, a fixed distance to the most distal component of the electronic imaging unit may be fixed with respect to the respective length of the section of the ear canal between the transition area and the eardrum. Such an arrangement may facilitate application by laypersons.
In addition, the otoscope may further comprising at least one mechanism configured to allow displacement of the electronic imaging unit or the at least one optical axis or at least one camera of the electronic imaging unit relative to the handle portion in conjunction with tilting it against the longitudinal axis. Such a combined mechanism, or two motion mechanisms combined with each other, especially two motion mechanisms which are controllable in dependence on each other, allow for “looking around the corner” more effectively. In particular, axially displacing or rotating an optical axis in conjunction with tilting the optical axis can enable observation of the entire eardrum, even from an observation point with a relatively small radial offset, or positioned unfavorably within the ear canal.
For hygienic reasons, the otoscope preferably further comprises an at least partially transparent probe cover configured to be put over the head portion. The probe cover may be made from a plastic material, preferably from a transparent plastic material. Such a probe cover may be designed as a single-use product that can be produced in larger numbers with low costs. The probe cover shall be transparent, at least at the locations where it covers an eccentric observation point, i.e. where it intersects an optical axis of the electronic imaging unit, so as to allow the electronic imaging unit to have a clear view onto the eardrum. The probe cover also inhibits contamination of the head portion of the otoscope comprising the electronic imaging unit, in particular when introducing the head portion into the patient's ear canal.
Preferably, the probe cover is adapted to be fixed to at least one section of either the head portion and/or the handle portion in such a way that the probe cover does not move relative to the handle portion during displacement of the electronic imaging unit or at least one optical axis or at least one camera by the motion mechanism. Otherwise, artifacts, such as earwax particles, adhering to the probe cover will depicted by the electronic imaging unit, even if the electronic imaging unit is displaced by the motion mechanism. This, however, would interfere with object identification and elimination of artifacts from the captured images.
The otoscope may further comprise a probe cover moving mechanism adapted to move at least a portion of the probe cover with respect to the electronic imaging unit or at least one optical axis or at least one camera. Thus, artifacts, such as earwax particles, adhering to the probe cover and obstructing the view of the electronic imaging unit or camera onto the eardrum can be moved away from the electronic imaging unit by the probe cover moving mechanism.
In particular, the probe cover moving mechanism can ensure that an optical axis of the electronic imaging unit can be arranged with a relatively large radial offset, especially without evoking the problem of any earwax particles obstructing visibility or with reduced probability of such earwax particles. Earwax particles are often arranged at an inner surface surrounding the ear canal. Thus, for an optical axis being arranged with a high radial offset, i.e. close to an inner lateral surface of the ear canal, there may be an increased likelihood of earwax particles adhering to the probe cover at a section covering the optical axis, thereby obstructing the view onto the eardrum. In other words: There may be an increased likelihood of earwax particles obstructing the view from an optical axis which is radially offset than from an optical axis which is arranged at least approximately centrically. The probe cover moving mechanism can ensure that the view onto the eardrum is not obstructed, even in case the optical axis is arranged with a maximum radial offset close to an inner lateral surface of the ear canal. Thus, the present invention is based on the finding that by providing a probe cover moving mechanism, observation of the eardrum from an eccentric observation point with a relatively large radial offset can be made more practicable and more reliable. A probe cover moving mechanism can ensure that the concept of “looking around the corner” is feasible and can be realized in a convenient way, even in case the ear canal is obstructed by several objects.
The probe cover moving mechanism can be provided e.g. in the form of a latch mechanism or an automatized mechanism which is driven by a motor. The probe cover moving mechanism allows for controlled, predefined relative displacement, especially in an axial direction, i.e. parallel to the longitudinal axis of the head portion. Preferably, the probe cover moving mechanism interact with a proximal portion of the probe cover and is configured for an axial motion or displacement of the probe cover or a portion of the probe cover, be it in a distal and/or in a proximal direction. As an alternative or in addition, the probe cover moving mechanism can be configured for rotating the probe cover.
Preferably, the probe cover is designed in a way that allows unfolding or peeling of portions of the probe cover in order to move portions of the probe cover contaminated e.g. with earwax away from the electronic imaging unit. The otoscope preferably contains mechanical means to move the probe cover against the electronic imaging unit or vice versa.
To illuminate the patient's ear canal and eardrum, the otoscope may further comprise at least one light source typically positioned at the distal end of the head portion, especially at the distal tip of the head portion. The term “light source” is understood to apply to any source emitting photons. A light source positioned at the distal end or tip ensures illumination of the ear canal, even in case the distal tip is only introduced as deep as a transition area between the two types of tissue. Distal light sources facilitate realization of the concept of “looking around the corner”.
Since geometrical restrictions limit the space at the distal end of the head portion, the light source is preferably formed by the distal end of a light guide. For example, the light guide may exhibit a diameter of less than 1 mm, preferably of less than 0.5 mm, more preferably of about 0.2 mm. The light guide may be connected to an LED located remote from the distal end of the head portion. The light guide may be e.g. a nylon light guide, preferably having a diameter of only about 0.2 mm to 1 mm. Alternatively, a light source may be formed e.g. by a small light emitting diode (LED) that is placed directly at the distal end of the head portion. The LED can ensure illumination with low energy consumption and minimum generation of heat.
The light guide can be made of polymethyl methacrylate (PMMA) or polyamide, especially polyamide 6.6. PMMA provides the advantage of good optical characteristics. Polyamide 6.6 provides the advantage of high flexibility. The light guide may allow placement of the light source at a distance from the distal end with less spatial constrains and space for means (e.g. a printed circuit board) for effective heat dissipation. Such an arrangement facilitates realization of the concept of “looking around the corner”, especially as the light guides may be arranged with a maximum radial offset without any risk of thermally damaging tissue. Effective heat dissipation reduces the impact of the otoscope on the tissue confining the ear canal, avoiding thermal irritation of the tissue.
It is advantageous, if the otoscope comprises a plurality of light sources at the distal end of the head portion, preferably with each light source being separately controllable. Thereby, the ear canal can be illuminated from a favorable eccentric illumination point, reducing e.g. shadowing. Also, by illuminating objects in the patient's ear canal from different positions, e.g. by sequentially switching on and off the individual light sources, it may also be envisaged to distinguish different objects in the ear, without necessarily having to displace the electronic imaging unit by a motion mechanism within the ear canal. An object relatively far away from the electronic imaging unit, such as the eardrum, will change its appearance only slightly when being illuminated from different positions at the distal end of the head portion. However, artifacts that are relatively close to the electronic imaging unit (such as hair and earwax) will change their appearance (position) drastically. The otoscope therefore preferably comprises means, in particular a logic unit, such as a microprocessor, adapted to distinguish different objects in the patient's ear based on images taken with the objects being illuminated from different positions.
Preferably, a logic unit is coupled with at least two of the light sources and is arranged for individually switching on and off the light sources and/or for individually varying the light intensity.
Additionally or alternatively, the at least one light source may be controllable in view of the color, so that it is possible to change the color of the light emitted by the light source. For example red color may be preferred to recognize an inflamed eardrum, wherein green color may be preferred to recognize earwax.
According to one specific embodiment, the otoscope comprises the logic unit, wherein the logic unit is coupled with at least two of the light sources and is arranged for individually switching on and off the light sources and/or for individually varying the light intensity. Individually switching on and off enables stereoscopic viewing, especially depth analysis along the optical axes due to changes in reflected light patterns. Also, segmented lighting of the ear canal can be carried out. For example, three light sources each illuminate a specific portion of the ear canal. Feedback regulation of each of the light sources allows for homogeneous illumination of the ear canal, especially based on different illumination levels. Preferably, a logic unit is coupled to each of the light sources, the logic unit allowing for feedback regulation and/or adjustment of illumination levels.
According to one specific embodiment, the otoscope comprises the logic unit, wherein the logic unit is arranged for adjusting an intensity of illumination provided by the least one light source, wherein the least one light source preferably is dimmable, especially continuously dimmable. Adjusting the illumination level facilitates identification of the eardrum, in particular in dependence on the degree of reddishness of the eardrum with respect to surrounding tissue and with respect to a specific intensity of illumination. Preferably, the logic unit comprises at least one dimmer switch.
Like the electronic imaging unit, the at least one light source is preferably positioned radially offset from the longitudinal axis of the head portion. Such a configuration allows illumination of the eardrum without the need to introduce the light source as deeply into the ear canal as it would be necessary, if the light source were placed centrally on the longitudinal axis of the head portion. The offset may be at least 1 mm, preferably at least 1.5 mm, more preferably at least 2 mm from the longitudinal axis. Preferably, the offset is maximum with respect to the confines of the outer diameter of the head portion. According to one embodiment, the offset is in the same range as a radial offset of the at least one optical axis. According to one embodiment, the radial offset of the at least one light source is as large as a radial offset of a camera of the electronic imaging unit. Such an arrangement is favorable in order to observe the entire eardrum or in order to reduce shadowing.
The radial offset preferably is in the range of 1.8 mm to 2.5 mm, more preferable 1.9 mm to 2.3 mm, further preferable 2.0 mm to 2.1 mm. Such a radial offset can ensure that light is effectively emitted onto the eardrum, irrespective of the relative position of a head portion of the otoscope within the ear canal, especially irrespective of any specific insertion depth into the bony part of the ear canal, i.e. the section confined by hard bone. According to one embodiment, the radial offset is not larger than the radial offset of the at least one optical axis. This arrangement can ensure that light is emitted within the ear canal, reflections from inner lateral surfaces of the ear canal being minimized.
Preferably, the at least one light source is positioned adjacent to the at least one optical axis, preferably in a distance (b) smaller than 2 mm, more preferable smaller than 1.5 mm, further preferable smaller than 1.3 mm, especially between 1 mm and 1.3 mm or between 0.6 mm and 0.8 mm. Such an arrangement can enable emission of light with respect to one specific camera or optical axis. In particular, shadowing can be reduced. Light can be emitted onto the eardrum from a favorable position, especially e.g. in a direction which is at least approximately parallel to the ear canal. Also, an arrangement close to the optical axis can ensure that the light source can easily be displaced in conjunction with the optical axis in order to position the light source at a favorable eccentric illumination point.
According to one embodiment, the otoscope exhibits at least two light sources or light guides which are arranged in a maximum distance (d) apart from each other, wherein the maximum distance (d) is at least 3.5 mm, more preferable at least 4 mm, further preferred in a range between 4.2 mm and 4.6 mm. Such an arrangement is favorable in order to observe the entire eardrum, especially without the need of rotating the camera or light source in a specific position. The relatively large distance can ensure that it is likely that one of the at least two, three or four light sources is arranged in a favorable eccentric illumination point.
Preferably, the at least one light source is arranged so as to maintain a predetermined distance with respect to the electronic imaging unit or the at least one optical axis, even when the electronic imaging unit or the at least one optical axis is displaced by the motion mechanism. Such a configuration is advantageous, because the predetermined distal relationship between the at least one light source and the optical axis allows for improved (automatic) image analysis. If a motion mechanism is provided, the motion mechanism preferably also displaces the at least one light source. If the light source is provided in the form of a light guide, the light guide should be sufficiently flexible to allow for such a displacement of the at least one light source. Preferably, the light guide is fixed distally within the head portion, wherein the light guide is elastic, the elasticity allowing for bending and/or twisting. Alternatively, the light guide may be rigid, wherein the entire lightning apparatus may be displaced in conjunction with the head portion.
According to one embodiment, the at least one light source is coupled with the motion mechanism, especially directly or via the electronic imaging unit, such that the motion mechanism allows for at least partial rotation of the at least one light source about an axis of rotation, wherein the axis of rotation preferably corresponds to the longitudinal axis. Rotating the light source in a favorable position can allow for observing the entire eardrum with a high reliability.
The at least one light source may be fixed at the electronic imaging unit, in particular laterally fixed at a camera of the electronic imaging unit or at a support accommodating at least one optical component of the electronic imaging unit or defining the least one optical axis. With such an arrangement, rotation of both the electronic imaging unit and the light source can be realized quite easily. Thereby, the motion mechanism only has to be coupled with one of these components.
According to one embodiment, the otoscope further comprises an infrared sensor unit positioned at the distal end of the head portion, especially centrically. Providing an otoscope comprising an infrared sensor unit for temperature detection in conjunction with an optical identification of objects allows for more reliable identification of the objects, e.g. of the eardrum. Providing an otoscope additionally with an infrared sensor unit allows for minimizing any risk of misdiagnosis. Pre-diagnosis may be facilitated. Temperature detection may assist a physician in carrying out diagnosis. End diagnosis will be carried out by the physician. Any more advanced or final disease diagnosis has to be carried out by the physician on the basis of other symptoms exhibited by the subject, which are observed by the physician, or by the physician's further examination.
The infrared sensor unit may be provided as a component of the electronic imaging unit, or as a separate sensor unit. The infrared sensor unit can be connected to a logic unit, the logic unit being configured for processing data from both the infrared sensor unit and the electronic imaging unit, especially simultaneously. Data acquired by the infrared sensor unit can be verified based on data acquired by the electronic imaging unit, and vice versa. The infrared sensor unit can be provided at same positions like positions discussed in context with the electronic imaging unit or the light sources. Likewise, the infrared sensor unit can be displaced in the same manner as discussed in context with the electronic imaging unit or the light sources.
As described above, the otoscope may further comprise a logic unit, such as a microprocessor. The logic unit may be adapted to control the electronic imaging unit and/or the at least one light source and/or an infrared sensor unit and/or any one of the motion mechanisms or moving mechanism. Also, the logic unit may analyze the images obtained by the electronic imaging unit e.g. in order to detect an inflammation of the eardrum and/or the inner part of the outer ear canal, and/or in order to compare two images obtained with the electronic imaging unit located at different positions within the ear and/or with the object illuminated from different positions, so as to identify and discriminate different objects in the patient's ear. The logic unit may further be adapted to generate or calculate a new image wherein predetermined objects that have been previously identified are eliminated.
According to one particular embodiment, the above mentioned object is achieved according to the present invention by an otoscope comprising: a handle portion allowing a user to manipulate the otoscope during its application; and a head portion exhibiting a substantially tapering form extending along a longitudinal axis of the head portion, wherein the head portion has a proximal end adjacent to the handle portion and a smaller distal end configured to be introduced in an ear canal of a patient's outer ear, wherein the otoscope further comprises an optical electronic imaging unit positioned at the distal end of the head portion, especially at a distal tip of the head portion, wherein the electronic imaging unit exhibits at least two, especially three or four, optical axis which are positioned radially offset from the longitudinal axis, wherein the distal end is configured for accommodating the electronic imaging unit in such a way that the radial offset can be maximum with respect to the diameter of the distal end, and wherein the electronic imaging unit exhibits beam splitter optics, especially provided as single injection molded part, or one part for each light path or optical axis, defining at least two of the optical axes, the at least two of the optical axes being arranged concentrically, especially rotationally symmetrically with respect to the longitudinal axis of the head portion. Such an otoscope provides the advantages as discussed above in context with the respective features.
According to one particular embodiment, the above mentioned object is achieved according to the present invention by an otoscope comprising: a handle portion allowing a user to manipulate the otoscope during its application; and a head portion exhibiting a substantially tapering form extending along a longitudinal axis of the head portion, wherein the head portion has a proximal end adjacent to the handle portion and a smaller distal end configured to be introduced in an ear canal of a patient's outer ear, wherein the otoscope further comprises an optical electronic imaging unit positioned at the distal end of the head portion, especially at a distal tip of the head portion, wherein the electronic imaging unit exhibits one optical axis which is positioned radially offset from the longitudinal axis, wherein the distal end is configured for accommodating the electronic imaging unit in such a way that the radial offset can be maximum with respect to the diameter of the distal end, wherein the electronic imaging unit comprises a miniature camera, the radial offset with respect to the optical axis or a middle axis of the camera being in the range of 1 mm to 2.5 mm, preferably 1.5 mm to 2 mm, especially at least 1.8 mm, and wherein the otoscope comprises a motion mechanism configured to allow displacement, especially rotation, of the camera relative to the handle portion. Such an otoscope provides the advantages as discussed above in context with the respective features.
The above mentioned object is achieved according to the present invention by an otoscope comprising: a handle portion allowing a user to manipulate the otoscope during its application; and a head portion exhibiting a substantially tapering form extending along a longitudinal axis of the head portion, wherein the head portion has a proximal end adjacent to the handle portion and a smaller distal end configured to be introduced in an ear canal of a patient's outer ear, wherein the otoscope further comprises an optical electronic imaging unit positioned at the distal end of the head portion, especially at a distal tip of the head portion, wherein the electronic imaging unit exhibits at least two, especially three or four, optical axis which are positioned radially offset from the longitudinal axis, wherein the distal end is configured for accommodating the electronic imaging unit in such a way that the radial offset can be maximum with respect to the diameter of the distal end, wherein the electronic imaging unit comprises at least two, especially three or four, miniature cameras, the radial offset with respect to the optical axis or a middle axis of the cameras preferably respectively being in the range of 1 mm to 3 mm, preferably 1.5 mm to 2.5 mm. A plurality of eccentric cameras provide favorable eccentric observation points, especially without the need for any motion mechanism.
According to the present invention, the above mentioned object is also achieved by an otoscope comprising: a handle portion allowing a user to manipulate the otoscope during its application; and a head portion exhibiting a substantially tapering form extending along a longitudinal axis of the head portion, wherein the head portion has a proximal end adjacent to the handle portion and a smaller distal end configured to be introduced in an ear canal of a patient's outer ear, wherein the otoscope further comprises an optical electronic imaging unit positioned at the distal end of the head portion, especially at a distal tip of the head portion, wherein the electronic imaging unit exhibits four optical axes which are positioned radially offset from the longitudinal axis, wherein the distal end is configured for accommodating the electronic imaging unit in such a way that the radial offset can be maximum with respect to the diameter of the distal end, wherein the electronic imaging unit further comprises a number of four to eight, especially four, light sources positioned radially offset from the longitudinal axis at the distal end, wherein at least one light source is correlated or allocated or attributed to a respective optical axis, and wherein the radial offset of the light sources is in the range of 1 mm to 2.5 mm. Correlating at least one light source with each optical axis, especially correlating four light source or five, six, seven or eight light sources with four optical axes, provides the advantage that the ear canal can be illuminated and analyzed from favorable eccentric illumination points as well as from favorable eccentric observation points, substantially irrespective of the relative position of a head portion of the otoscope within the ear canal, or substantially irrespective of the relative (rotational) orientation position of the head portion within the ear canal.
In case any reference sign is not explicitly described in a respective figure, it is referred to the other figures. In other words: Like reference characters refer to the same parts or the same type or group of device throughout the different views.